Didn't ask close friend to be bridesmaid and regret it now...should I address it at some point?

My fiance and I decided on a three-person wedding party each. He wanted to have his three best friends and no more. I initially wanted to have a few more but was OK with three too. I have a longtime friend from college who I knew would be a bit hurt if I did not ask her and I was in her wedding. Same with my sister-in-law (I was in her wedding too). Asked another good friend who lives out-of-state to be my maid of honor.

I also have a close group of three friends since high school (12+ years). I see them probably more than any of the other girls (we all get together for drinks, etc.). We rarely hang out one-on-one, it's typically group gatherings, and I'm closer to one of them (I'll call her Friend A) more than the other two, however it would be hurtful/awkward to ask one and not all three. Had my fiance and I agreed on a bigger wedding party, I would have asked all of them though.

I have not been sure how Friend A felt about this. She's also engaged and I honestly did not know what she was planning for a bridal party or how close she felt her and I were (good friends versus best friends). She has a sister, several female cousins and other friends and I didn't want her to feel some type of obligation to pick me if she didn't feel we were close. Well tonight, her fiance mentioned that we (high school friend group) were her best friends. That was surprising to hear. He later asked me one-on-one how big my bridal party was and I could tell Friend A was listening in the background. I told him we were having a small wedding party, he changed the subject, and I felt like Friend A was kind of off the rest of the night.

Anyway I'm wondering how to address this or if it needs to be addressed. In hindsight I wish I'd insisted on a bigger bridal party and asked all three of those girls, but what's done is done. I also wonder if she was planning to ask me to be a bridesmaid and now isn't sure what to do since I did not ask her. Any advice?